Elongated electroacoustic transducer with integral reinforced mounting flanges



Aug. 2, 1960 w. T. HARRIS 2,947,969

ELONGATED ELECTROACOUSTIC TRANSDUCER WITH INTEGRAL REINFORCED MOUNTING FLANGES Flled Sept 8 1954 INVENTOR M431? 7: Mme/s will] ATTORNEYS .tes

ELONGATED ELECTROA'COUSTIC TRANSDUCER gg'gr r lg rnomr. REINFORCED MOUNTING Wilbur T. Harris, Southbury, 'Conn., assignor to The Harris Transducer Corporation, Southbury, 'Conn., a

corporation of Connecticut Filed Sept. 8, 1954, Ser. No. 454,712

3 Claims. (Cl. 340-5 My invention relates to an improved shock-mounting structure, and 1n particular to a mounting for an electro- .acoustic transducer adapted to underwater use.

:It is an object of the invention to provide improved means of the character indicated.

It is another object to provide an improved flexible mounting for atransducer which will withstand substantial abuse and yet will so freely support the transducer as to isolate the same from mechanical shock sustained by the supporting frame.

tion in conjunction with the accompanying drawings. .In said drawings, which show, for illustrative purposes y, Preferred fa m f. the inve o l ig. :1 is a sectional yiew taken substantially through a smgle radial plane of a mounted transducer 'incorporao m features of ,theinvent qa. ce pa being Sh w s mew a pers ec ive. from th sectional Plane and t lead lines being illustrated diagrammatically, in order better to illustrate the relationship;

Fig. 2 is an enlarged fragmentary view in perspective and partly broken away to illustrate a modification; and

Fig. 3 is a View in elevation of a further modification, with certain parts broken and shown in section to reveal mounting details.

Briefly stated, my invention contemplates application to the mounting of an elongated transducer, such as an electroacoustic transducer suitable for underwater use. The transducer is secured within an opening in or spaced between rigid frame-support means, and flexible flange or web means bonded to or integral with the transducer extend radially from the axis of the transducer in overlapping relation with parts of the frame support, near the inner limit thereof. The radial space between the transducer and the inner limit of the frame opening is preferably substantial, so that substantial radial length of yieldable support is provided.

In one general form of the invention, the yieldable web or flange is elongated and substantially coextensive with the length of the transducer, and it extends radially outwardly from the axis of the transducer at angularly spaced locations. In the other general form, the yieldable Web or flange is an annular skirt at a particular axial location along the length of the transducer, and, if desired, a plurality of such skirts may be provided at such axial spacings and in such plurality as dictated by application requirements.

Referring to Fig. l of the drawings, my invention is shown in application to the mounting of an elongated cylindrical transducer within an opening 11 defined between spaced opposed frame means 12-12. The frame means 12-42 may be part of the same rigid strip, merely slotted at 11 to provide the mounting space; alternaatent 2,947,959 i atented Aug. 2, .1969

'tively, the frame .means HP-12. may be separate membelrs rigidly secured (by means not shown) .to each 0 er.

Theitransdu'cer 10 may be of the magnetostrictive variety, but in the form shown I suggest that the principal element of the transducer is an electrostrictive cylinder 13 having electrode fo ils ,14-15 on the inner and outer walls thereof, for deriving an electrical response to pressure fluctuations incident on the transducer to produce an instantaneous potential shown by the plus and minus signs on the lead lines in Fig. 1. In order that the response may be primarily to externally incident pressure fluctuations, I show pressure-release means, such as a layer 16 of cork, Corprene, cardboard, or the like, radially within the 'electrostrictive cylinder 13 and permanently held in place by an internal potting 17 of suitable plastic.

The transducer proper may also include an outer protective sheath '18 of sound-transmitting plastic intimately bonded to the electrode 14 and to the electrostrictive cylinder 13; the plastic used for potting and for the cover 18 may be one of a variety of hard plastics, as, for example, epoxy resins. For further protection against abuse, an outer'boot or jacket 19-may be bonded 'to the hard plastic layer 18, and I prefer that this outer boot be of rubberthe described transducer within the frame opening 11 .by

means of webs -or flanges 21 extending radially of the transducer 10 andoverlapping the supporting frame means lL-IZ' to permit ruggedsecuring, as by bolts 20 spaced along the length -of the regions of overlap. The webs or flanges 21 extend radially from the axis of the transducer and may be bonded to or formed integrally with the boot 191; .my preference is to form both the boot 19 and the flange means 21 at the same time, so that the flange means may assuredly be integral with the transducer.

In order to enhance the securing effectiveness of bolts 20, I prefer internally to reinforce the flange means 21, as by metallic means 22 bonded within the flange means 21. In the form shown in Fig. l, the reinforcing means 22 is an elongated strip for each flange. The strip 22 may be coextensive with the longitudinal extent of the flange, but is preferably bonded only within that part of the flange which overlaps the securing frame 12. Stated in other words, the radial extent of the flange 21 is preferably such that a substantial unreinforced portion exists for the radial space between the transducer and the inner limits of the opening 11, thus providing free suspension, particularly insofar as transverse movement (relative to frame means 12-12) is concerned.

In Fig. 2, I show a slight modification, in which the metal reinforcement means 22 within the web or flange 21 is a washer, it being understood that such washers are provided in such plurality as necessary for the plurality of bolts 20 needed to secure the flange 21 to the supporting frame 12--12.

In Fig. 3, I show a further modification applicable to a situation in which the isolation from shock is to be primarily along the axis of the elongated transducer 25, as distinguished from the predominantly transverse isolation of Figs. 1 and 2. In the Fig. 3 situation, the supporting flange means may comprise a single flange 26 of yieldable material and formed as an annular skirt continuously joined to the outer periphery of the transducer 25; again, I prefer that the outer periphery of the transducer 25 be defined by a boot of rubber-like material and that the flange means 26 be formed integrally therewith. To accommodate the mounting flange 26, the frame support 27 may, at least at the location of flange 26, comprise a single rigid plate having an opening 28' in which the transducer 25 may be positioned with substantial radial clearance, as shown. As for'the case of Fig. 1, the outer limit of the yieldable flange 2 6 preferably is bonded to an internal reinforcement means with the region of overlap, which in the case of Fig. 3

means a ring or annular reinforcement member 29, about the axis of the transducer.

Depending upon the length of the transducer 25, one or more of the described radial-plane type of flange will be necessary to provide the necessary support. In the .form shown, I merely suggest provision of a plurality of such flanges by inclusion of the additional flange 31 at the lower end of the transducer, secured to another part 27' of the frame means.

It will be seen that I have described a relatively simple and highly eifectivc shock mounting for elongated transducers. The mounting is particularly applicable to underwater transducers which are subjected to severe abuse and prolonged underwater exposure. The basic construction lends itself to provision of shock isolation, either predominantly along the axis of the transducer or predominantly transversely thereto, as dictated by operational requirements; even though isolation may appear predominantly in certain directions, the predominance is not great because all support for the transducer is de-- ing an elongated structure electrically responsive to incident pressure fluctuations and including a peripherally continuous outer boot of pressure-transmitting material in intimate pressure-transmitting relation with said structure, said mounting means including flange means of yieldable material extending generally radially of the axis of said transducer means, a metal portion bonded within said flange essentially only in the region adjacent the outermost edge, and a frame support having an opening defined by an inner edge overlapping the outer part of said flange means, whereby a substantial part of the radial length of said flange may be unsupported and may therefore yieldably support said transducer, and anchoring bolts passing through the flange means and through said metal portion and engaging said frame support.

2. The combination of claim 1, in which said metal portion comprises an elongated strip substantially coextensive with the length of said flange means, there being a plurality of securing bolts passing through said strip and through said flange means at spaced locations along the length.

3. The combination of claim 1, in which said metal portion comprises at each bolted location a washer through which the bolt passes.

References Cited in the file of this patent UNITED STATES PATENTS 2,033,165 Williams Mar. 10, 1936 2,294,674 Lord Sept. 1, 1942 2,357,740 Hickin Sept. 5, 1944 2,399,820 Morgan May 7, 1946 2,478,207 Robinson Aug. 9, 1949 2,575,339 Fitzgerald Nov. 20, 1951 2,617,874 Lewis Nov. 11, 1952 2,638,577 Harris May 12, 1953 2,672,945 Harris et a1 Mar. 23, 1954 2,681,142 Cohen June 15, 1954 2,728,063 Renner Dec. 20, 1955 2,761,117 Green Aug. 28, 1956 2,768,364 Camp Oct. 23, 1956 2,831,175 Janssen Apr. 15, 1958 

